The present invention relates to a metallic mold for injection-molding of golf balls.
In molding operations in which golf balls are produced by using a metallic mold, molding flashes at the injection gate portion of the metallic mold inevitably adheres to the golf balls, and immediately after the molding operation is completed, they have molding flashes still left on their surfaces. In a conventional method of removing molding flashes from the golf balls, the molding flashes are removed by hand from them.
However, the manual removal of the molding flashes is inefficient. For this reason, a proposal for overcoming this disadvantage is recently made such as, for example, a golf ball with molding flashes after being subjected to injection-molding operation is rectified in the position thereof by means of a position, rectifying machine for balls, such as disclosed in the Japanese Patent-Application Gazette to Public Inspection No. 81059-1984 (See FIG. 11 of the accompanying drawings which is hereinafter described.). According to this proposal all the molding flashes are located in a horizontal plane for their easy removal. Thereafter, the golf ball, rectified in the position thereof, is automatically rid of the molding flashes by using a method and a machine for removing molding flashes from golf balls, which is disclosed in the Japanese Patent Publication Gazette No. 25911-1988.
However, it has proved that in the foregoing conventional method, the following problem remains unsolved. When in a ball-position rectifying machine, such as shown in FIG. 11, molding flashes b which adhere to the equatorial position (the parting line) of a golf ball e at the injection gate portion of a metallic mold used to mold it are engaged by stoppers c, c of the rectifying machine, and the golf ball e is rectified in the position thereof by rotating it, so that the molding flashes b are moved with respect to the stoppers to remove them.
That is to say, the injection-gate portions arranged for a single golf ball in the metallic mold are limited in number, depending upon an arrangement of dimples on the surface of the golf ball.
Also, the molding flashes b which adhere to a golf ball intended to be produced, at the injection-gate portions of the metallic mold are smaller in their size as they jut from the metallic mold, owing to a surface dimple arrangement of the golf ball. Moreover, all the molding flashes b are not detached at the same positions from the metallic mold, and therefore, they do not remain constant in their size.
For these reasons, the probability is low that the molding flashes b of the golf ball e are always engaged by the stoppers c, c shown in FIG. 11. Therefore, a positional rectification of the golf ball mounted in the ball-position rectifying machine is extremely difficult in practice, because the molding flashes have the foregoing dimensional characteristics. As a result, it is substantially impossible to apply the flash removing machine of FIG. 11 to the golf balls intended to be completed.
It is therefore an object of the present invention to provide for a metallic mold which constantly ensures positional rectification of a golf ball having molding flashes when it is mounted in a ball-position rectifying machine, before it is ground by means of a flash removing apparatus, to thereby achieve the complete removal of molding flashes from the golf balls.
Also, it is another object of the present invention to provide for a metallic mold which produces golf balls good in their surface appearance and inconspicuous in marks remaining after their molding flashes have been ground by means of a flash removing apparatus.